Operation Flashpoint: Cold War Crisis

Step 1: FOV change

Open \Operation Flashpoint\Users\your name\UserInfo.cfg in text editor and modify values.

For 16:10
fovLeft=1.2;
uiTopLeftX=0.083333;
uiBottomRightX=0.916667;

For 16:9
fovLeft=1.333333;
uiTopLeftX=0.125;
uiBottomRightX=0.875;
_[hr]_
Step 2: Interface change
Download OFP Aspect Ratio package. Copy /Files/Aspect_Ratio.hpp to the game root directory (where the exe is) and /Files/OFP Resistance/Config.cpp, Resource.cpp to the /res/bin in your game directory.

Then open Aspect_Ratio.hpp in text editor and modify definition according to the instructions.
For 16:10
#define aspect_ratio_16_10

For 16:9
#define aspect_ratio_16_9